The project will investigate the role of inhabitation in acoustic processing in the mature and developing brainstem auditory system of the domestic chicken. This stay involves a three-pronged approach that constitute the specific aims: 1) to asses the influence of GABAergic input on both pre and postsynaptic elements in thee nucleus in the nucleus magnocellularis; 2) to asses the relative contribution of the primary excitatory and inhibitory inputs to processing of neurons in the superior olivary nucleus; 3) to describe and investigate influences on the efficacy and temporal characteristics of inhibitory inputs to nucleus magnocellularis and nucleus laminar is during development. Aim 1 will be addressed in vivo using multibarrel electrodes which allow for the pharmacological analysis of the contribution of various GABA receptor electrodes which allow for the pharmacological analysis of the contribution of various GABA receptor subtypes which are differently expressed in pre and postsynaptic terminals in nucleus magnocellularis. Aims 2 and 3 will autolysin in vitro preparation that will allow for the experimental segregation of inputs to brainstem nuclei and provide access to the biophysical properties of the neurons. These studies will contribute to a more complete understanding of acoustic processing in vertebrate nervous systems. Furthmore, developmental studies may reveal factors that could play a role in recovery of function in deaf patients. Understanding developmental influences on synaptic properties may contribute to the development of appropriate therapies for patients deprived of acoustic stimulation early in life.